Sheet metal components are frequently connected to one another by means of bending and subsequently painted. Due to the gap formation in the flange area, the paint penetration is impaired by this design. Consequently, the paint provides insufficient protection against corrosion (e.g. crevice corrosion) in the flange area. These are the reasons why such constructions are provided with a flange adhesive prior to the paint application. This flange adhesive serves for filling out the flange and thereby protecting these areas against corrosion. Due to manufacturing-related tolerances, exact dosing of the adhesive is usually not possible. In series production, this results in overfilling or under filling in the flange area. Overfilled flange areas lead to problems during the painting process and therefore need to be elaborately removed at great expense prior to the painting process. Under filled flange areas are only protected to a limited degree and undesirable corrosion damage may occur during the operation depending on the amount of under filling.
On a car door, one joint at risk of corrosion is located, in particular, on its underside, where the outer and the inner metal sheets are connected by means of bending, because rain water tends to flow to this location from other parts of the door and only evaporates slowly due to the protected position on the inner side of the door.
EP 2 383 053 A1 discloses a car door, on which a groove is formed on the outer metal sheet and a filling material layer is inserted between the outer metal sheet and an edge of an inner metal sheet that engages into the groove. In order to ensure that this filling material layer adjoins the inner and outer metal sheets so seamlessly that no water can be admitted in between, the filling material layer must consist of an adhesive that adheres to the metal sheets with sufficient strength for preventing the metal sheets from being spread apart in any way. The time required for such an adhesive to cure is incompatible with the short process cycles in sheet metal processing.
Accordingly, there is a need for a sheet metal component that on the one hand makes it possible to achieve effective corrosion protection by means of painting and on the other hand is suitable for a manufacture with short cycle times.